The present invention relates to an automated component mounting apparatus capable of sequentially performing the picking up of components, particularly electric and/or electronic component parts such as chips, one at a time, the transfer thereof from a pick-up station to a mounting station and the mounting thereof on a support such as, for example, a printed circuit board, in an automated manner.
The mounting machine of the type referred to above is well known and is currently utilized in the field of art to which the present invention pertains. A typical mounting machine now used in an electrical industry for automatically mounting miniature electronic component parts (hereinafter referred to as chips) of leadless type on a printed circuit board of boards one at a time utilizes a suction head for sucking the chips one at a time at a pick-up station. The transportation and the subsequent mounting of the chips are carried out while the chip is sucked onto the suction head by the effect of a suction force developed in the suction head. However, so long as the conventional machine is concerned, it has often occurred that the chip sucked onto the suction head is displaced in position relative to the suction head during either or both of the pick-up and transportation thereof, thereby posing a problem associated with the mounting precision.
In order to avoid any possible displacement in position of the chip relative to the suction head, as shown in FIG. 1 of the accompanying drawings illustrating the suction head in longitudinal sectional view, the suction opening of the head 1 has been so designed as to assume a shape convenient and suited to guide the chip 2 being sucked. Even this method lacks a sufficient reliability because the chip sucked onto the suction head tends to tilt and/or the tip of the suction head tends to contact the printed circuit board at the time of mounting thereon onto the printed circuit board.
Apart from the method shown in FIG. 2, another method has been contemplated and is currently used wherein a correcting device is installed on and along the path of transportation of the chips from the pick-up station to a mounting station for correcting the position of the chip relative to the suction head by temporarily placing the chip once picked up at the correcting device and then sucking the chip again in a corrected position. Although the employment of the correcting device is advantageous and effective to minimize an incorrect mounting of the chip on the printed circuit board, not only does it render the machine as a whole to be expensive, but also a loss of time occurs during the transportation of the chip from the pick-up station to the mounting station. In any event, depending on the design of the correcting device, there may be the possibility that the chip placed on and sucked again onto the suction head may displace relative to the suction head.
The U.S. Pat. No. 4,135,630 discloses a similar apparatus effective to avoid the problem inherent in the employment of the correcting device. However, even in the apparatus of this U.S. patent, the following problem is often found to occur when the chip has been inclined or misaligned. Specifically, if attempt is made to correct the position of the chip 2 from four directions, not only does the chip 2 once picked up by the suction head 4 tend to fall by gravity, but also the chip 2 tends to be incorrectly held by the suction head 4 with its one end sucked thereto as shown in FIG. 2(a), or with a corner portion thereof sucked onto the suction head as shown in FIG. 2(b).